Signaling of video coding tools supporting various chroma format

ABSTRACT

A method of decoding an encoded video. The method includes obtaining the encoded video bitstream and determining whether a chroma array type of a video sequence included in the encoded video bitstream is a first chroma array type indicating that the video sequence includes multiple color planes and that the multiple color planes are jointly. In addition, based on determining that the chroma array type is not the first chroma array type, the method further includes setting a value of at least one syntax element to zero without parsing the at least one syntax element from the encoded video bitstream, and based on the value of the at least one syntax element being zero, decoding the video sequence without applying at least one tool corresponding to the at least one syntax element.

CROSS-REFERENCE TO RELATED APPLICATION

This application is continuation of U.S. application Ser. No. 17/104,688filed on Nov. 25, 2020, which claims priority from 35 U.S.C. § 119 toU.S. Provisional Application No. 62/942,003, filed on Nov. 29, 2019, inthe United States Patent & Trademark Office, and U.S. ProvisionalApplication No. 62/947,385, filed on Dec. 12, 2019, in the United StatesPatent & Trademark Office, the disclosures of which are incorporatedherein by reference in their entireties.

FIELD

The disclosed subject matter relates to video coding and decoding, andmore specifically, to signaling of video coding tools supporting variouschroma formats.

BACKGROUND

ITU-T VCEG (Q6/16) and ISO/IEC MPEG (JTC 1/SC 29/WG 11) published theH.265/HEVC (High Efficiency Video Coding) standard in 2013 (version 1)2014 (version 2) 2015 (version 3) and 2016 (version 4). In 2015, thesetwo standard organizations jointly formed the JVET (Joint VideoExploration Team) to explore the potential of developing the next videocoding standard beyond HEVC. In October 2017, they issued the Joint Callfor Proposals on Video Compression with Capability beyond HEVC (CfP). ByFeb. 15, 2018, total 22 CfP responses on standard dynamic range (SDR),12 CfP responses on high dynamic range (HDR), and 12 CfP responses on360 video categories were submitted, respectively. In April 2018, allreceived CfP responses were evaluated in the 122 MPEG/10th JVET meeting.As a result of this meeting, JVET formally launched the standardizationprocess of next-generation video coding beyond HEVC. The new standardwas named Versatile Video Coding (VVC), and JVET was renamed as JointVideo Expert Team.

SUMMARY

In an embodiment, there is provided a method of decoding an encodedvideo bitstream, including obtaining the encoded video bitstream;determining whether a chroma array type of a video sequence included inthe encoded video bitstream is a first chroma array type indicating thatthe video sequence includes multiple color planes and that the multiplecolor planes are jointly encoded; based on determining that the chromaarray type is not the first chroma array type, setting a value of atleast one syntax element to zero without parsing the at least one syntaxelement from the encoded video bitstream; and based on the value of theat least one syntax element being zero, decoding the video sequencewithout applying at least one tool corresponding to the at least onesyntax element.

In an embodiment, there is provided a device for decoding an encodedvideo bitstream, including at least one memory configured to storeprogram code; and at least one processor configured to read the programcode and operate as instructed by the program code, the program codeincluding: obtaining code configured to cause the at least one processorto obtain the encoded video bitstream; determining code configured tocause the at least one processor to determine whether a chroma arraytype of a video sequence included in the encoded video bitstream is afirst chroma array type indicating that the video sequence includesmultiple color planes and that the multiple color planes are jointlyencoded; first setting code configured to cause the at least oneprocessor to, based on determining that the chroma array type is not thefirst chroma array type, set a value of at least one syntax element tozero without parsing the at least one syntax element from the encodedvideo bitstream; and first decoding code configured to cause the atleast one processor to, based on the value of the at least one syntaxelement being zero, decode the video sequence without applying at leastone tool corresponding to the at least one syntax element.

In an embodiment, there is provided a non-transitory computer-readablemedium storing instructions, the instructions including: one or moreinstructions that, when executed by one or more processors of a devicefor decoding an encoded video bitstream, cause the one or moreprocessors to: obtain the encoded video bitstream; determine whether achroma array type of a video sequence included in the encoded videobitstream is a first chroma array type indicating that the videosequence includes multiple color planes and that the multiple colorplanes are jointly encoded; based on determining that the chroma arraytype is not the first chroma array type, set a value of at least onesyntax element to zero without parsing the at least one syntax elementfrom the encoded video bitstream; and based on the value of the at leastone syntax element being zero, decode the video sequence withoutapplying at least one tool corresponding to the at least one syntaxelement.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features, the nature, and various advantages of the disclosedsubject matter will be more apparent from the following detaileddescription and the accompanying drawings in which:

FIG. 1 is a schematic illustration of a simplified block diagram of acommunication system in accordance with an embodiment.

FIG. 2 is a schematic illustration of a simplified block diagram of acommunication system in accordance with an embodiment.

FIG. 3 is a schematic illustration of a simplified block diagram of adecoder in accordance with an embodiment.

FIG. 4 is a schematic illustration of a simplified block diagram of anencoder in accordance with an embodiment.

FIGS. 5A-5C illustrate flowcharts of example processes for decoding anencoded video bitstream in accordance with embodiments.

FIG. 6 is a flowchart of an example process for decoding an encodedvideo bitstream in accordance with embodiments.

FIG. 7 is a schematic illustration of a computer system in accordancewith an embodiment.

DETAILED DESCRIPTION

FIG. 1 illustrates a simplified block diagram of a communication system(100) according to an embodiment of the present disclosure. The system(100) may include at least two terminals (110-120) interconnected via anetwork (150). For unidirectional transmission of data, a first terminal(110) may code video data at a local location for transmission to theother terminal (120) via the network (150). The second terminal (120)may receive the coded video data of the other terminal from the network(150), decode the coded data and display the recovered video data.Unidirectional data transmission may be common in media servingapplications and the like.

FIG. 1 illustrates a second pair of terminals (130, 140) provided tosupport bidirectional transmission of coded video that may occur, forexample, during videoconferencing. For bidirectional transmission ofdata, each terminal (130, 140) may code video data captured at a locallocation for transmission to the other terminal via the network (150).Each terminal (130, 140) also may receive the coded video datatransmitted by the other terminal, may decode the coded data and maydisplay the recovered video data at a local display device.

In FIG. 1 , the terminals (110-140) may be illustrated as servers,personal computers and smart phones but the principles of the presentdisclosure may be not so limited. Embodiments of the present disclosurefind application with laptop computers, tablet computers, media playersand/or dedicated video conferencing equipment. The network (150)represents any number of networks that convey coded video data among theterminals (110-140), including for example wireline and/or wirelesscommunication networks. The communication network (150) may exchangedata in circuit-switched and/or packet-switched channels. Representativenetworks include telecommunications networks, local area networks, widearea networks and/or the Internet. For the purposes of the presentdiscussion, the architecture and topology of the network (150) may beimmaterial to the operation of the present disclosure unless explainedherein below.

FIG. 2 illustrates, as an example for an application for the disclosedsubject matter, the placement of a video encoder and decoder in astreaming environment. The disclosed subject matter can be equallyapplicable to other video enabled applications, including, for example,video conferencing, digital TV, storing of compressed video on digitalmedia including CD, DVD, memory stick and the like, and so on.

A streaming system may include a capture subsystem (213), that caninclude a video source (201), for example a digital camera, creating afor example uncompressed video sample stream (202). That sample stream(202), depicted as a bold line to emphasize a high data volume whencompared to encoded video bitstreams, can be processed by an encoder(203) coupled to the camera (201). The encoder (203) can includehardware, software, or a combination thereof to enable or implementaspects of the disclosed subject matter as described in more detailbelow. The encoded video bitstream (204), depicted as a thin line toemphasize the lower data volume when compared to the sample stream, canbe stored on a streaming server (205) for future use. One or morestreaming clients (206, 208) can access the streaming server (205) toretrieve copies (207, 209) of the encoded video bitstream (204). Aclient (206) can include a video decoder (210) which decodes theincoming copy of the encoded video bitstream (207) and creates anoutgoing video sample stream (211) that can be rendered on a display(212) or other rendering device (not depicted). In some streamingsystems, the video bitstreams (204, 207, 209) can be encoded accordingto certain video coding/compression standards. Examples of thosestandards include ITU-T Recommendation H.265. Under development is avideo coding standard informally known as Versatile Video Coding or VVC.The disclosed subject matter may be used in the context of VVC.

FIG. 3 may be a functional block diagram of a video decoder (210)according to an embodiment of the present disclosure.

A receiver (310) may receive one or more codec video sequences to bedecoded by the decoder (210); in the same or another embodiment, onecoded video sequence at a time, where the decoding of each coded videosequence is independent from other coded video sequences. The codedvideo sequence may be received from a channel (312), which may be ahardware/software link to a storage device which stores the encodedvideo data. The receiver (310) may receive the encoded video data withother data, for example, coded audio data and/or ancillary data streams,that may be forwarded to their respective using entities (not depicted).The receiver (310) may separate the coded video sequence from the otherdata. To combat network jitter, a buffer memory (315) may be coupled inbetween receiver (310) and entropy decoder/parser (320) (“parser”henceforth). When receiver (310) is receiving data from a store/forwarddevice of sufficient bandwidth and controllability, or from anisosychronous network, the buffer (315) may not be needed, or can besmall. For use on best effort packet networks such as the Internet, thebuffer (315) may be required, can be comparatively large and canadvantageously of adaptive size.

The video decoder (210) may include a parser (320) to reconstructsymbols (321) from the entropy coded video sequence. Categories of thosesymbols include information used to manage operation of the decoder(210), and potentially information to control a rendering device such asa display (212) that is not an integral part of the decoder but can becoupled to it, as was shown in FIG. 3 . The control information for therendering device(s) may be in the form of Supplementary EnhancementInformation (SEI messages) or Video Usability Information (VUI)parameter set fragments (not depicted). The parser (320) mayparse/entropy-decode the coded video sequence received. The coding ofthe coded video sequence can be in accordance with a video codingtechnology or standard, and can follow principles well known to a personskilled in the art, including variable length coding, Huffman coding,arithmetic coding with or without context sensitivity, and so forth. Theparser (320) may extract from the coded video sequence, a set ofsubgroup parameters for at least one of the subgroups of pixels in thevideo decoder, based upon at least one parameter corresponding to thegroup. Subgroups can include Groups of Pictures (GOPs), pictures,sub-pictures, tiles, slices, bricks, macroblocks, Coding Tree Units(CTUs) Coding Units (CUs), blocks, Transform Units (TUs), PredictionUnits (PUs) and so forth. A tile may indicate a rectangular region ofCU/CTUs within a particular tile column and row in a picture. A brickmay indicate a rectangular region of CU/CTU rows within a particulartile. A slice may indicate one or more bricks of a picture, which arecontained in an NAL unit. A sub-picture may indicate an rectangularregion of one or more slices in a picture. The entropy decoder/parsermay also extract from the coded video sequence information such astransform coefficients, quantizer parameter values, motion vectors, andso forth.

The parser (320) may perform entropy decoding/parsing operation on thevideo sequence received from the buffer (315), so to create symbols(321).

Reconstruction of the symbols (321) can involve multiple different unitsdepending on the type of the coded video picture or parts thereof (suchas: inter and intra picture, inter and intra block), and other factors.Which units are involved, and how, can be controlled by the subgroupcontrol information that was parsed from the coded video sequence by theparser (320). The flow of such subgroup control information between theparser (320) and the multiple units below is not depicted for clarity.

Beyond the functional blocks already mentioned, decoder 210 can beconceptually subdivided into a number of functional units as describedbelow. In a practical implementation operating under commercialconstraints, many of these units interact closely with each other andcan, at least partly, be integrated into each other. However, for thepurpose of describing the disclosed subject matter, the conceptualsubdivision into the functional units below is appropriate.

A first unit is the scaler/inverse transform unit (351). Thescaler/inverse transform unit (351) receives quantized transformcoefficient as well as control information, including which transform touse, block size, quantization factor, quantization scaling matrices,etc. as symbol(s) (321) from the parser (320). It can output blockscomprising sample values, that can be input into aggregator (355).

In some cases, the output samples of the scaler/inverse transform (351)can pertain to an intra coded block; that is: a block that is not usingpredictive information from previously reconstructed pictures, but canuse predictive information from previously reconstructed parts of thecurrent picture. Such predictive information can be provided by an intrapicture prediction unit (352). In some cases, the intra pictureprediction unit (352) generates a block of the same size and shape ofthe block under reconstruction, using surrounding already reconstructedinformation fetched from the current (partly reconstructed) picture(358). The aggregator (355), in some cases, adds, on a per sample basis,the prediction information the intra prediction unit (352) has generatedto the output sample information as provided by the scaler/inversetransform unit (351).

In other cases, the output samples of the scaler/inverse transform unit(351) can pertain to an inter coded, and potentially motion compensatedblock. In such a case, a Motion Compensation Prediction unit (353) canaccess reference picture memory (357) to fetch samples used forprediction. After motion compensating the fetched samples in accordancewith the symbols (321) pertaining to the block, these samples can beadded by the aggregator (355) to the output of the scaler/inversetransform unit (in this case called the residual samples or residualsignal) so to generate output sample information. The addresses withinthe reference picture memory form where the motion compensation unitfetches prediction samples can be controlled by motion vectors,available to the motion compensation unit in the form of symbols (321)that can have, for example X, Y, and reference picture components.Motion compensation also can include interpolation of sample values asfetched from the reference picture memory when sub-sample exact motionvectors are in use, motion vector prediction mechanisms, and so forth.

The output samples of the aggregator (355) can be subject to variousloop filtering techniques in the loop filter unit (356). Videocompression technologies can include in-loop filter technologies thatare controlled by parameters included in the coded video bitstream andmade available to the loop filter unit (356) as symbols (321) from theparser (320), but can also be responsive to meta-information obtainedduring the decoding of previous (in decoding order) parts of the codedpicture or coded video sequence, as well as responsive to previouslyreconstructed and loop-filtered sample values.

The output of the loop filter unit (356) can be a sample stream that canbe output to the render device (212) as well as stored in the referencepicture memory for use in future inter-picture prediction.

Certain coded pictures, once fully reconstructed, can be used asreference pictures for future prediction. Once a coded picture is fullyreconstructed and the coded picture has been identified as a referencepicture (by, for example, parser (320)), the current reference picture(358) can become part of the reference picture buffer (357), and a freshcurrent picture memory can be reallocated before commencing thereconstruction of the following coded picture.

The video decoder 210 may perform decoding operations according to apredetermined video compression technology that may be documented in astandard, such as ITU-T Rec. H.265. The coded video sequence may conformto a syntax specified by the video compression technology or standardbeing used, in the sense that it adheres to the syntax of the videocompression technology or standard, as specified in the videocompression technology document or standard and specifically in theprofiles document therein. Also necessary for compliance can be that thecomplexity of the coded video sequence is within bounds as defined bythe level of the video compression technology or standard. In somecases, levels restrict the maximum picture size, maximum frame rate,maximum reconstruction sample rate (measured in, for example megasamplesper second), maximum reference picture size, and so on. Limits set bylevels can, in some cases, be further restricted through HypotheticalReference Decoder (HRD) specifications and metadata for HRD buffermanagement signaled in the coded video sequence.

In an embodiment, the receiver (310) may receive additional (redundant)data with the encoded video. The additional data may be included as partof the coded video sequence(s). The additional data may be used by thevideo decoder (210) to properly decode the data and/or to moreaccurately reconstruct the original video data. Additional data can bein the form of, for example, temporal, spatial, or SNR enhancementlayers, redundant slices, redundant pictures, forward error correctioncodes, and so on.

FIG. 4 may be a functional block diagram of a video encoder (203)according to an embodiment of the present disclosure.

The encoder (203) may receive video samples from a video source (201)(that is not part of the encoder) that may capture video image(s) to becoded by the encoder (203).

The video source (201) may provide the source video sequence to be codedby the encoder (203) in the form of a digital video sample stream thatcan be of any suitable bit depth (for example: 8 bit, 10 bit, 12 bit, .. . ), any colorspace (for example, BT.601 Y CrCB, RGB, . . . ) and anysuitable sampling structure (for example Y CrCb 4:2:0, Y CrCb 4:4:4). Ina media serving system, the video source (201) may be a storage devicestoring previously prepared video. In a videoconferencing system, thevideo source (203) may be a camera that captures local image informationas a video sequence. Video data may be provided as a plurality ofindividual pictures that impart motion when viewed in sequence. Thepictures themselves may be organized as a spatial array of pixels,wherein each pixel can comprise one or more sample depending on thesampling structure, color space, etc. in use. A person skilled in theart can readily understand the relationship between pixels and samples.The description below focusses on samples.

According to an embodiment, the encoder (203) may code and compress thepictures of the source video sequence into a coded video sequence (443)in real time or under any other time constraints as required by theapplication. Enforcing appropriate coding speed is one function ofController (450). Controller controls other functional units asdescribed below and is functionally coupled to these units. The couplingis not depicted for clarity. Parameters set by controller can includerate control related parameters (picture skip, quantizer, lambda valueof rate-distortion optimization techniques, . . . ), picture size, groupof pictures (GOP) layout, maximum motion vector search range, and soforth. A person skilled in the art can readily identify other functionsof controller (450) as they may pertain to video encoder (203) optimizedfor a certain system design.

Some video encoders operate in what a person skilled in the are readilyrecognizes as a “coding loop”. As an oversimplified description, acoding loop can consist of the encoding part of an encoder (430)(“source coder” henceforth) (responsible for creating symbols based onan input picture to be coded, and a reference picture(s)), and a (local)decoder (433) embedded in the encoder (203) that reconstructs thesymbols to create the sample data a (remote) decoder also would create(as any compression between symbols and coded video bitstream islossless in the video compression technologies considered in thedisclosed subject matter). That reconstructed sample stream is input tothe reference picture memory (434). As the decoding of a symbol streamleads to bit-exact results independent of decoder location (local orremote), the reference picture buffer content is also bit exact betweenlocal encoder and remote encoder. In other words, the prediction part ofan encoder “sees” as reference picture samples exactly the same samplevalues as a decoder would “see” when using prediction during decoding.This fundamental principle of reference picture synchronicity (andresulting drift, if synchronicity cannot be maintained, for examplebecause of channel errors) is well known to a person skilled in the art.

The operation of the “local” decoder (433) can be the same as of a“remote” decoder (210), which has already been described in detail abovein conjunction with FIG. 3 . Briefly referring also to FIG. 4 , however,as symbols are available and en/decoding of symbols to a coded videosequence by entropy coder (445) and parser (320) can be lossless, theentropy decoding parts of decoder (210), including channel (312),receiver (310), buffer (315), and parser (320) may not be fullyimplemented in local decoder (433).

An observation that can be made at this point is that any decodertechnology except the parsing/entropy decoding that is present in adecoder also necessarily needs to be present, in substantially identicalfunctional form, in a corresponding encoder. For this reason, thedisclosed subject matter focusses on decoder operation. The descriptionof encoder technologies can be abbreviated as they are the inverse ofthe comprehensively described decoder technologies. Only in certainareas a more detail description is required and provided below.

As part of its operation, the source coder (430) may perform motioncompensated predictive coding, which codes an input frame predictivelywith reference to one or more previously-coded frames from the videosequence that were designated as “reference frames.” In this manner, thecoding engine (432) codes differences between pixel blocks of an inputframe and pixel blocks of reference frame(s) that may be selected asprediction reference(s) to the input frame.

The local video decoder (433) may decode coded video data of frames thatmay be designated as reference frames, based on symbols created by thesource coder (430). Operations of the coding engine (432) mayadvantageously be lossy processes. When the coded video data may bedecoded at a video decoder (not shown in FIG. 4 ), the reconstructedvideo sequence typically may be a replica of the source video sequencewith some errors. The local video decoder (433) replicates decodingprocesses that may be performed by the video decoder on reference framesand may cause reconstructed reference frames to be stored in thereference picture cache (434). In this manner, the encoder (203) maystore copies of reconstructed reference frames locally that have commoncontent as the reconstructed reference frames that will be obtained by afar-end video decoder (absent transmission errors).

The predictor (435) may perform prediction searches for the codingengine (432). That is, for a new frame to be coded, the predictor (435)may search the reference picture memory (434) for sample data (ascandidate reference pixel blocks) or certain metadata such as referencepicture motion vectors, block shapes, and so on, that may serve as anappropriate prediction reference for the new pictures. The predictor(435) may operate on a sample block-by-pixel block basis to findappropriate prediction references. In some cases, as determined bysearch results obtained by the predictor (435), an input picture mayhave prediction references drawn from multiple reference pictures storedin the reference picture memory (434).

The controller (450) may manage coding operations of the video coder(430), including, for example, setting of parameters and subgroupparameters used for encoding the video data.

Output of all aforementioned functional units may be subjected toentropy coding in the entropy coder (445). The entropy coder translatesthe symbols as generated by the various functional units into a codedvideo sequence, by loss-less compressing the symbols according totechnologies known to a person skilled in the art as, for exampleHuffman coding, variable length coding, arithmetic coding, and so forth.

The transmitter (440) may buffer the coded video sequence(s) as createdby the entropy coder (445) to prepare it for transmission via acommunication channel (460), which may be a hardware/software link to astorage device which would store the encoded video data. The transmitter(440) may merge coded video data from the video coder (430) with otherdata to be transmitted, for example, coded audio data and/or ancillarydata streams (sources not shown).

The controller (450) may manage operation of the encoder (203). Duringcoding, the controller (450) may assign to each coded picture a certaincoded picture type, which may affect the coding techniques that may beapplied to the respective picture. For example, pictures often may beassigned as one of the following frame types:

An Intra Picture (I picture) may be one that may be coded and decodedwithout using any other frame in the sequence as a source of prediction.Some video codecs allow for different types of Intra pictures,including, for example Independent Decoder Refresh Pictures. A personskilled in the art is aware of those variants of I pictures and theirrespective applications and features.

A Predictive picture (P picture) may be one that may be coded anddecoded using intra prediction or inter prediction using at most onemotion vector and reference index to predict the sample values of eachblock.

A Bi-directionally Predictive Picture (B Picture) may be one that may becoded and decoded using intra prediction or inter prediction using atmost two motion vectors and reference indices to predict the samplevalues of each block. Similarly, multiple-predictive pictures can usemore than two reference pictures and associated metadata for thereconstruction of a single block.

Source pictures commonly may be subdivided spatially into a plurality ofsample blocks (for example, blocks of 4×4, 8×8, 4×8, or 16×16 sampleseach) and coded on a block-by-block basis. Blocks may be codedpredictively with reference to other (already coded) blocks asdetermined by the coding assignment applied to the blocks' respectivepictures. For example, blocks of I pictures may be codednon-predictively or they may be coded predictively with reference toalready coded blocks of the same picture (spatial prediction or intraprediction). Pixel blocks of P pictures may be coded non-predictively,via spatial prediction or via temporal prediction with reference to onepreviously coded reference pictures. Blocks of B pictures may be codednon-predictively, via spatial prediction or via temporal prediction withreference to one or two previously coded reference pictures.

The video coder (203) may perform coding operations according to apredetermined video coding technology or standard, such as ITU-T Rec.H.265. In its operation, the video coder (203) may perform variouscompression operations, including predictive coding operations thatexploit temporal and spatial redundancies in the input video sequence.The coded video data, therefore, may conform to a syntax specified bythe video coding technology or standard being used.

In an embodiment, the transmitter (440) may transmit additional datawith the encoded video. The video coder (430) may include such data aspart of the coded video sequence. Additional data may comprisetemporal/spatial/SNR enhancement layers, other forms of redundant datasuch as redundant pictures and slices, Supplementary EnhancementInformation (SEI) messages, Visual Usability Information (VUI) parameterset fragments, and so on.

VVC draft 7 has adopted technologies that assume that a video sequenceto be encoded has multiple color planes and the color planes may beencoded jointly. However, in some situations, either when the video ismonochrome, or when the color planes of the video are required to beencoded independently, then these joint color plane coding tools are nolonger applicable. In order to support these situations, embodimentsprovide syntax and semantics, that are beyond the VCC draft 7, todisable these joint color plane coding tools when needed.

VVC Draft 7 intends to support the coding of monochrome video and thecoding of the three colour components of the 4:4:4 chroma format videoseparately. In order to support these applications, VCC Draft 7 defineda variable called ChromaArrayType to enable or disable the relatedcoding tools that are or are not applicable when the input video ismonochrome and when the colour components of the video are required tobe encode separately and independently.

In VVC Draft 7, depending on the value of separate_colour_plane_flag,the value of the variable ChromaArrayType is assigned as follows: Ifseparate_colour_plane_flag is equal to 0, ChromaArrayType is set equalto chroma_format_idc. Otherwise, if separate_colour_plane_flag is equalto 1, ChromaArrayType is set equal to 0.

When ChromaArrayType is 0, this may mean that the input video is eithermonochrome or 4:4:4 with separately coded colour planes. VVC Draft 7intends to disable the coding tools that are not applicable tomonochrome video and to the video that required to encode each colourcomponent of the video as if each component is monochrome. However, VCCDraft 7 is not able to disable some of these coding tools whenChromaArrayType is 0 such as the coding tools enabled bysps_joint_cbcr_enabled_flag or pps_joint_cbcr_qp_offset_present_flag.Embodiments relate to modifications to VVC Draft 7 to disable somecoding tools whenever the input video is monochrome or 4:4:4 withseparatly coded colour planes.

The syntax in VVC Draft 7 is italicized in the following Table 1, Table2, and Table 3.

TABLE 1 Sequence parameter set RBSP syntax from VVC Draft 7 Descrip- torseq_parameter_set_rbsp( ) {  sps_decoding_parameter_set_id u(4) sps_video_parameter_set_id u(4)  sps_max_sub_layers_minus1 u(3) sps_reserved_zero_4bits u(4)  sps_ptl_dpb_hrd_params_present_flag u(1) if( sps_ptl_dpb_hrd_params_present_flag )   profile_tier_level( 1,sps_max_sub_layers_minus1 )  gdr_enabled_flag u(1) sps_seq_parameter_set_id u(4)  chroma_format_idc u(2)  if(chroma_format_idc = = 3 )   separate_colour_plane_flag u(1) ref_pic_resampling_enabled_flag u(1)  sps_seq_parameter_set_id ue(v) chroma_format_idc ue(v)  if( chroma_format_idc = = 3 )  separate_colour_plane_flag u(1)  pic_width_max_in_luma_samples ue(v) pic_height_max_in_luma_samples ue(v)  sps_log2_ctu_size_minus5 u(2) subpics_present_flag u(1)   sps_num_subpics_minus1 u(8)   for( i = 0; i<= sps_num_subpics_minus1; i++ ) {    subpic_ctu_top_left_x[ i ] u(v)   subpic_ctu_top_left_y[ i ] u(v)    subpic_width_minus1[ i ] u(v)   subpic_height_minus1[ i ] u(v)    subpic_treated_as_pic_flag[ i ]u(1)    loop_filter_across_subpic_enabled_flag[ i ] u(1)   }  } sps_subpic_id_present_flag u(1)  if( sps_subpics_id_present_flag ) {  sps_subpic_id_signalling_present_flag u(1)   if(sps_subpics_id_signalling_present_flag ) {    sps_subpic_id_len_minus1ue(v)    for( i = 0; i <= sps_num_subpics_minus1; i++ )    sps_subpic_id[ i ] u(v)   }  }  bit_depth_minus8 ue(v) min_qp_prime_ts_minus4 ue(v)  sps_weighted_pred_flag u(1) sps_weighted_bipred_flag u(1)  log2_max_pic_order_cnt_lsb_minus4 u(4) sps_poc_msb_flag u(1)  if( sps_poc_msb_flag )   poc_msb_len_minus1ue(v)  if( sps_max_sub_layers_minus1 > 0 )  sps_sub_layer_dpb_params_flag u(1)  if(sps_ptl_dpb_hrd_params_present_flag )   dpb_parameters( 0,sps_max_sub_layers_minus1, sps_sub_layer_dpb_params flag ) long_term_ref_pics_flag u(1)  inter_layer_ref_pics_present_flag u(1) sps_idr_rpl_present_flag u(1)  rpl1_same_as_rpl0_flag u(1)  for( i = 0;i < !rpl1_same_as_rpl0_flag ? 2 : 1; i++ )   num_ref_pic_lists_in_sps[ i] ue(v)   for( j = 0; j < num_ref_pic_lists_in_sps[ i ]; j++)   ref_pic_list_struct( i, j )  }  if( ChromaArrayType != 0 )  qtbtt_dual_tree_intra_flag u(1) log2_min_luma_coding_block_size_minus2 ue(v) partition_constraints_override_enabled_flag u(1) sps_log2_diff_min_qt_min_cb_intra_slice_luma ue(v) sps_log2_diff_min_qt_min_cb_inter_slice ue(v) sps_max_mtt_hierarchy_depth_inter_slice ue(v) sps_max_mtt_hierarchy_depth_intra_slice_luma ue(v)  if(sps_max_mtt_hierarchy_depth_intra_slice_luma != 0 ) {  sps_log2_diff_max_bt_min_qt_intra_slice_luma ue(v)  sps_log2_diff_max_tt_min_qt_intra_slice_luma ue(v)  }  if(sps_max_mtt_hierarchy_depth_inter_slice != 0 ) {  sps_log2_diff_max_bt_min_qt_inter_slice ue(v)  sps_log2_diff_max_tt_min_qt_inter_slice ue(v)  }  if(qtbtt_dual_tree_intra_flag ) {  sps_log2_diff_min_qt_min_cb_intra_slice_chroma ue(v)  sps_max_mtt_hierarchy_depth_intra_slice_chroma ue(v)   if(sps_max_mtt_hierarchy_depth_in-   tra_slice_chroma != 0 ) {   sps_log2_diff_max_bt_min_qt_intra_slice_chroma ue(v)   sps_log2_diff_max_tt_min_qt_intra_slice_chroma ue(v)   }  } sps_max_luma_transform_size_64_flag u(1)  

u(1)  if( ChromaArrayType != 0 ) {   same_qp_table_for_chroma u(1)  numQpTables = same_qp_table_for_chroma ? 1 : (sps_joint_cbcr_enabled_flag ? 3 : 2 )   for( i = 0; i < numQpTables; i++) {    qp_table_start_minus26[ i ] se(v)   num_points_in_qp_table_minust [ i ] ue(v)    for( j = 0; j <=num_points in_qp_ta-    ble_minus1[ i ]; j++ ) {    delta_qp_in_val_minus1[ i ][ j ] ue(v)     delta_qp_diff_val[ i ][ j] ue(v)    }   }  }  sps_sao_enabled_flag u(1)  sps_alf_enabled_flagu(1)  sps_transform_skip_enabled_flag u(1)  if(sps_transform_skip_enabled_flag )   sps_bdpcm_enabled_flag u(1)  if(sps_bdpcm_enabled_flag && chroma_format_idc = = 3 )   

u(1)  sps_ref_wraparound_enabled_flag u(1)  if(sps_ref_wraparound_enabled_flag )   sps_ref wraparound_offset_minus1ue(v)  sps_temporal_mvp_enabled_flag u(1)  if(sps_temporal_mvp_enabled_flag )   sps_sbtmvp_enabled_flag u(1) sps_amvr_enabled_flag u(1)  sps_bdof_enabled_flag u(1)  if(sps_bdof_enabled_flag )   sps_bdof_pic_present_flag u(1) sps_smvd_enabled_flag u(1)  sps_dmvr_enabled_flag u(1)  if(sps_dmvr_enabled_flag)   sps_dmvr_pic_present_flag u(1) sps_mmvd_enabled_flag u(1)  sps_isp_enabled_flag u(1) sps_mrl_enabled_flag u(1)  sps_mip_enabled_flag u(1)  if(ChromaArrayType != 0 )   sps_cclm_enabled_flag u(1)   if(sps_cclm_enabled_flag && chroma_format_idc = = 1 ) [Ed. (JC): shouldsps_cclm_colocated_chroma_flag also be signalled for 422 case since it'sused in the decoding process, to be confirmed]  sps_cclm_colocated_chroma_flag u(1)  sps_mts_enabled_flag u(1)  if(sps_mts_enabled_flag ) {   sps_explicit_mts_intra_enabled_flag u(1)  sps_explicit_mts_inter_enabled_flag u(1)  }  sps_sbt_enabled_flag u(1) sps_affine_enabled_flag u(1)  if( sps_affine_enabled_flag ) {  sps_affine_type_flag u(1)   sps_affine_amvr_enabled_flag u(1)  sps_affine_prof_enabled_flag u(1)   if( sps_affine_prof_enabled_flag )   sps_prof pic_present_flag u(1)  }  if( chroma_format_idc = = 3 ) {   

u(1)   

u(1)

 sps_bcw_enabled_flag u(1)  sps_ibc_enabled_flag u(1) sps_ciip_enabled_flag u(1)  if( sps_mmvd enabled_flag )  sps_fpel_mmvd_enabled_flag u(1)  sps_triangle_enabled_flag u(1) sps_lmcs_enabled_flag u(1)  sps_lfnst_enabled_flag u(1) sps_ladf_enabled_flag u(1)  if( sps_ladf_enabled_flag) {  sps_num_ladf_intervals_minus2 u(2)  sps_ladf_lowest_interval_qp_offset se(v)   for( i = 0; i <sps_num_ladf_intervals_minus2 + 1; i++ ) {    sps_ladf_qp_offset[ i ]se(v)    sps_ladf_delta_threshold_minus1[ i ] ue(v)   }  } sps_scaling_list_enabled_flag u(1) sps_loop_filter_across_virtual_bound- u(1)  aries_disabled_present_flag if( sps_loop_filter_across_virtual_bound-  aries_disabled_present flag) {   sps_num_ver_virtual_boundaries u(2)   for( i = 0; i < sps num vervirtual boundaries; i++ )     sps_virtual_boundaries_pos_x[ i ] u(13)  sps_num_hor_virtual_boundaries u(2)   for( i = 0; i <sps_num_hor_virtual_boundaries; i++ )     sps_virtual_boundaries_pos_y[i ] u(13)  }  if( sps_ptl_dpb_hrd_params_present_flag ) {  sps_general_hrd_params_present_flag u(1)   if(sps_general_hrd_params_present_flag ) {     general_hrd_parameters( )    if( sps_max_sub_layers_minus1 > 0 )     sps_sub_layer_cpb_params_present_flag u(1)     firstSubLayer =sps_sub_lay-     er_cpb_params_present_flag ? 0 :      sps_max_sub_layers_minus1     ols_hrd_parameters( firstSubLayer,   sps_max_sub_layers_minus1 )   }  }  vui_parameters_present_flag u(1) if( vui_parameters_present_flag )   vui_parameters( ) sps_extension_flag u(1)  if( sps_extension_flag )   while(more_rbsp_data( ) )    sps_extension_data_flag u(1)  rbsp_trailing_bits() }

TABLE 2 Picture parameter set RBSP syntax from VVC Draft 7 Descrip- torpic_parameter_set rbsp( ) {  pps_pic_parameter_set_id ue(v) pps_seq_parameter_set_id u(4)  pic_width_in_luma_samples ue(v) pic_height_in_luma_samples ue(v)  conformance_window_flag u(1)  if(conformance_window_flag ) {   conf_win_left_offset ue(v)  conf_win_right_offset ue(v)   conf_win_top_offset ue(v)  conf_win_bottom_offset ue(v)  }  scaling_window_flag u(1)  if(scaling_window_flag ) {   scaling_win_left_offset ue(v)  scaling_win_right_offset ue(v)   scaling_win_top_offset ue(v)  scaling_win_bottom_offset ue(v)  }  output_flag_present_flag u(1) mixed_nalu_types_in_pic_flag u(1) pps_subpic_id_signalling_present_flag u(1)  if(pps_subpics_id_signalling_present_flag ) {   pps_num_subpics_minus1ue(v)   pps_subpic_id_len_minus1 ue(v)   for( i = 0; i <=pps_num_subpic_minus1; i++ )    pps_subpic_id[ i ] u(v)  } no_pic_partition_flag u(1)  if( !no_pic_partition_flag ) {  pps_log2_ctu_size_minus5 u(2)   num_exp_tile_columns_minus1 ue(v)  num_exp_tile_rows_minus1 ue(v)   for( i = 0; i <=num_exp_tile_columns_minus1; i++ )    tile_column_width_minus1[ i ]ue(v)   for( i = 0; i <= num_exp_tile_rows_minus1; i++ )   tile_row_height_minus1[ i ] ue(v)   rect_slice_flag u(1)   if(rect_slice_flag )    single_slice_per_subpic_flag u(1)   if(rect_slice_flag && !single_slice_per_subpic_flag ) {   num_slices_in_pic_minus1 ue(v)    tile_idx_delta_present_flag u(1)   for( i = 0; i < num_slices_in_pic minus1; i++ ) {    slice_width_in_tiles_minus1[ i ] ue(v)    slice_height_in_tiles_minus1[ i ] ue(v)     if(slice_width_in_tiles_minus1[ i ] = = 0 &&        slice_height_in_tiles_minus1[ i ] = = 0 ) {      num_slices_in_tile_minus1[ i ] ue(v)       numSlicesInTileMinus1 =      num_slices_in_tile_minus1[ i ]       for( j = 0; j <numSlicesInTileMinus1; j++ )        slice_height_in_ctu_minus1[ i++ ]ue(v)      }      if( tile_idx_delta_present_flag && i <     num_slices_in_pic_minus1 )       tile_idx_delta[ i ] se(v)    }   }  loop_filter_across_tiles_enabled_flag u(1)  loop_filter_across_slices_enabled_flag u(1)  } entropy_coding_sync_enabled_flag u(1)  if( !no_pic_partition_flag | | entropy_coding_sync_enabled_flag )   entry_point_offsets_present_flagu(1)  cabac_init_present_flag u(1)  for( i = 0; i < 2; i++ )  num_ref_idx_default_active_minus1[ i ] ue(v)  rpl1_idx_present_flagu(1)  init_qp_minus26 se(v)  if( sps_transform_skip_enabled_flag )  log2_transform_skip_max_size_minus2 ue(v)  cu_qp_delta_enabled_flagu(1)  

se(v)  

se(v)  

u(1)  if( pps_joint_cbcr_qp_offset_present_flag )  pps_joint_cbcr_qp_offset_value se(v)  

u(1)  

u(1)  if( pps_cu_chroma_qp_offset_list_enabled_flag ) {  chroma_qp_offset_list_len_minus1 ue(v)   for( i = 0; i <=chroma_qp_offset_list_len_minus1; i++ ) {    cb_qp_offset_list_[ i ]se(v)    cr_qp_offset_list_[ i ] se(v)    if(pps_joint_cbcr_qp_offset_present_flag )     joint_cbcr_qp_offset_list[ i] se(v)   }  }  pps_weighted_pred_flag u(1)  pps_weighted_bipred_flagu(1)  deblocking_filter_control_present_flag u(1)  if(deblocking_filter_control_present_flag ) {  deblocking_filter_override_enabled_flag u(1)  pps_deblocking_filter_disabled_flag u(1)   if(!pps_deblocking_filter_disabled_flag ) {    pps_beta_offset_div2 se(v)   pps_tc_offset_div2 se(v)   }  } constant_slice_header_params_enabled_flag u(1)  if(constant_slice_header_params_enabled_flag ) {  pps_dep_quant_enabled_idc u(2)   for( i = 0; i < 2; i++ )   pps_ref_pic_list_sps_idc[ i ] u(2)   pps_mvd_l1_zero_idc u(2)  pps_collocated_from_10_idc u(2)  pps_six_minus_max_num_merge_cand_plus1 ue(v)  pps_max_num_merge_cand_mi- ue(v)   nus_max_num_triangle_cand_plus1  } picture_header_extension_present_flag u(1) slice_header_extension_present_flag u(1)  pps_extension_flag u(1)  if(pps_extension_flag )   while( more_rbsp_data( ) )   pps_extension_data_flag u(1)  rbsp_trailing_bits( ) }

TABLE 3 Adaptive loop filter data syntax from VVC Draft 7 Descriptoralf_data( ) {  alf_luma_filter_signal_flag u(1)   

  u(1)  if( alf_luma_filter_signal_flag ) {   alf_luma_clip_flag u(1)  alf_luma_num_filters_signalled_minus1 ue(v)   if(alf_luma_num_filters_signalled_minus1 > 0 ) {    for( filtIdx = 0;filtIdx < NumAlfFilters; filtIdx++ )     alf_luma_coeff_delta_idx[filtIdx ] u(v)   }   for( sfIdx = 0; sfIdx <= alf_luma num filterssignalled minus1 ; sfIdx++ ) {    for( j = 0; j < 12; j++ ) {    alf_luma_coeff_abs[ sfIdx ][ j ] uek(v)     if( alf_luma_coeff_abs[sfIdx ][ j ] )      alf_luma_coeff_sign[ sfIdx ][ j ] u(1)    }   }  if( alf_luma_clip_flag ) {    for( sfIdx = 0; sfIdx <=alf_luma_num_filters_ signalled_minus1; sfIdx++ ) {     for( j = 0; j <12; j++ )      alf_luma_clip_idx[ sfIdx ][ j ] u(2)    }   }  }  if(alf_chroma_filter_signal_flag ) {   alf_chroma_num_alt_filters_minus1ue(v)    for( altIdx = 0; altIdx <= alf_chroma_num_alt_ filters_minus1 ;altIdx++ ) {    alf_chroma_clip_flag[ altIdx ] u(1)    for( j = 0; j <6; j++ ) {     alf_chroma_coeff_abs[ altIdx ][ j ] uek(v)     if(alf_chroma_coeff_abs[ altIdx ][ j ] > 0 )      alf_chroma_coeff_sign[altIdx ][ j ] u(1)    }    if( alf_chroma_clip_flag[ altIdx ] ) {    for( j = 0; j < 6; j++ )      alf_chroma_clip_idx[ altIdx ][ j ]u(2)    }   }  } }

Embodiments may relate to handling the sps_joint_cbcr_enabled_flag whenChromaArrayType equals to 0 as follows. As shown in Table 4, whenChromaArrayType equals to 0, sps_joint_cbcr_enabled_flag is not parsedand inferred to be 0 such that joint Cb and Cr residual coding as achroma residual coding is disabled to avoid unnecessary decodingprocesses. The text changes are highlighted in italics and texts<<inside double angle brackets>> indicates deleted texts.

TABLE 4 Handling on sps joint cbcr enabled flag Descriptorseq_parameter_set_rbsp( ) { ...  << sps_joint_cbcr_enabled_flag>><<u(1)>>  if( ChromaArrayType != 0 ) { u(1)    

    same_qp_table_for_chroma u(1)   numQpTables =same_qp_table_for_chroma ? 1 : ( sps_joint_cbcr_enabled_flag ? 3 : 2 )  for( i = 0; i < numQpTables; i++ ) {    qp_table_start_minus26[ i ]se(v)    num_points_in_qp_table_minus1[ i ] ue(v)    for( j = 0; j <=num_points_in_qp_table_minus1[ i ]; j++ ) {     delta_qp_in_val_minus1[i ][ j ] ue(v)     delta_qp_diff_val[ i ][ j ] ue(v)    }   }  } ... }

sps_joint_cbcr_enabled_flag equal to 0 may specify that the joint codingof chroma residuals is disabled. sps_joint_cbcr_enabled_flag equal to 1may specify that the joint coding of chroma residuals is enabled. Whensps_joint_cbcr_enabled_flag is not present, it may be inferred to beequal to 0.

When ChromaArrayType is 0, a video component shall be encoded as if itis monochrome or 4:4:4 with separately coded colour planes. As shown inthe italicized syntax in Table 1, Table 2 and 3, the syntax elementspps_cb_qp_offset, pps_cr_qp_offset,pps_joint_cbcr_qp_offset_present_flag,pps_slice_chroma_qp_offsets_present_flag,pps_cu_chroma_qp_offset_list_enabled_flag, alf_chroma_filter_signal_flagare signaled independently on ChromaArrayType. When ChromaArrayType is0, these flags could have a value of 1 which enables coding tools thatare not applicable to encoding a video component as if it is monochromeor 4:4:4 with separately coded colour planes. This results inconflicting signaling between ChromaArrayType and the abovementionedsyntax elements.

To ensure there are no conflicts in the signaling betweenChromaArrayType and the related syntax elements, embodiments relate tomodifications to a syntax of a sequence parameter set RBSP, a pictureparameter set RBSP syntax and adaptive loop filter data syntax.

Embodiments are described in the form of text modifications relative tothe specification text of VVC Draft 7 shown below Table 5, Table 6,Table 7, and Table 8. The text changes are highlighted in italics.

TABLE 5 Modified sequence parameter set RBSP syntax De- scrip- torseq_parameter_set_rbsp( ) {  sps_decoding_parameter_set_id u(4) sps_video_parameter_set_id u(4)  sps_max_sub_layers_minus1 u(3) sps_reserved_zero_4bits u(4)  sps_ptl_dpb_hrd_params_present_flag u(1) if( sps_ptl_dpb_hrd_params_present_flag )   profile_tier_level( 1,sps_max_sub_layers_minus1 )  gdr_enabled_flag u(1) sps_seq_parameter_set_id u(4)  chroma_format_idc u(2)  if(chroma_format_idc = = 3 )   separate_colour_plane_flag u(1) ref_pic_resampling_enabled_flag u(1)  pic_width_max_in_luma_samplesue(v)  pic_height_max_in_luma_samples ue(v)  sps_log2_ctu_size_minus5u(2)  subpics_present_flag u(1)   sps_num_subpics_minus1 u(8)   for( i =0; i < = sps_num_subpics_minus1; i++ ) {    subpic_ctu_top_left_x[ i ]u(v)    subpic_ctu_top_left_y[ i ] u(v)    subpic_width_minus1[ i ] u(v)   subpic_height_minus1[ i ] u(v)    subpic_treated_as_pic_flag[ i ]u(1)    loop_filter_across_subpic_enabled_flag[ i ] u(1)   }  } sps_subpic_id_present_flag u(1)  if( sps_subpics_id_present_flag ) {  sps_subpic_id_signalling_present_flag u(1)   if(sps_subpics_id_signalling_present_flag ) {    sps_subpic_id_len_minus1ue(v)    for( i = 0; i <= sps_num_subpics_minus1; i++ )    sps_subpic_id[ i ] u(v)   }  }  bit_depth_minus8 ue(v) min_qp_prime_ts_minus4 ue(v)  sps_weighted_pred_flag u(1) sps_weighted_bipred_flag u(1)  log2_max_pic_order_cnt_lsb_minus4 u(4) sps_poc_msb_flag u(1)  if( sps_poc_msb_flag )  poc_msb_len_minus1 ue(v) if( sps_max_sub_layers_minus1 > 0 )  sps_sub_layer_dpb_params_flag u(1) if( sps_ptl_dpb_hrd_params_present_flag )  dpb_parameters( 0,sps_max_sub_layers_minus1, sps_sub_layer_dpb_params_flag ) long_term_ref_pics_flag u(1)  inter_layer_ref_pics_present_flag u(1) sps_idr_rpl_present_flag u(1)  rpl1_same_as_rpl0_flag u(1)  for( i = 0;i < !rpl1_same_as_rpl0_flag ? 2 : 1; i++ ) {   num_ref_pic_lists_in_sps[i ] ue(v)   for( j = 0; j < num_ref_pic_lists_in_sps[ i ]; j++)   ref_pic_list struct( i, j )  }  if( ChromaArrayType != 0 )  qtbtt_dual_tree_intra_flag u(1) log2_min_luma_coding_block_size_minus2 ue(v) partition_constraints_override_enabled_flag u(1) sps_log2_diff_min_qt_min_cb_intra_slice_luma ue(v) sps_log2_diff_min_qt_min_cb_inter_slice ue(v) sps_max_mtt_hierarchy_depth_inter_slice ue(v) sps_max_mtt_hierarchy_depth_intra_slice_luma ue(v)  if(sps_max_mtt_hierarchy_depth_intra_slice_luma != 0 ) {  sps_log2_diff_max_bt_min_qt_intra_slice_luma ue(v)  sps_log2_diff_max_tt_min_qt_intra_slice_luma ue(v)  }  if(sps_max_mtt_hierarchy_depth_inter_slice != 0 ) {  sps_log2_diff_max_bt_min_qt_inter_slice ue(v)  sps_log2_diff_max_tt_min_qt_inter_slice ue(v)  }  if(qtbtt_dual_tree_intra_flag ) {  sps_log2_diff_min_qt_min_cb_intra_slice_chroma ue(v) sps_max_mtt_hierarchy_depth_intra_slice_chroma ue(v)  if(sps_max_mtt_hierarchy_depth_intra_slice_chroma != 0 ) {  sps_log2_diff_max_bt_min_qt_intra_slice_chroma ue(v)  sps_log2_diff_max_tt_min_qt_intra_slice_chroma ue(v)   }  } sps_max_luma_transform_size_64_flag u(1)  if( ChromaArrayType != 0 ) {u(1)   sps_joint_cbcr_enabled_flag   same_qp_table_for_chroma u(1)  numQpTables = same_qp_table_for_chroma ? 1 : (sps_joint_cbcr_enabled_flag ? 3 : 2 )   for( i = 0; i < numQpTables; i++) {    qp_table_start_minus26[ i ] se(v)   num_points_in_qp_table_minus1[ i ] ue(v)    for( j = 0; j <=num_points_in_qp_table_minus1[ i ]; j++ ) {     delta_qp_in_val_minus1[i ][ j ] ue(v)     delta_qp_diff_val[ i ][ j ] ue(v)    }   }  } sps_sao_enabled_flag u(1)  sps_alf_enabled_flag u(1) sps_transform_skip_enabled_flag u(1)  if(sps_transform_skip_enabled_flag )   sps_bdpcm_enabled_flag u(1)  if(sps_bdpcm_enabled_flag && ChromaArrayType= =3)  sps_bdpcm_chroma_enabled_flag u(1)  sps_ref_wraparound_enabled_flagu(1)  if( sps_ref_wraparound_enabled_flag )  sps_ref_wraparound_offset_minus1 ue(v)  sps_temporal_mvp_enabled_flagu(1)  if( sps_temporal_mvp_enabled_flag )   sps_sbtmvp_enabled_flag u(1) sps_amvr_enabled_flag u(1)  sps_bdof_enabled_flag u(1)  if(sps_bdof_enabled_flag )   sps_bdof_pic_present_flag u(1) sps_smvd_enabled_flag u(1)  sps_dmvr_enabled_flag u(1)  if(sps_dmvr_enabled_flag)   sps_dmvr_pic_present_flag u(1) sps_mmvd_enabled_flag u(1)  sps_isp_enabled_flag u(1) sps_mrl_enabled_flag u(1)  sps_mip_enabled_flag u(1)   if(ChromaArrayType != 0 )   sps_cclm_enabled_flag u(1)   if(sps_cclm_enabled_flag && chroma_format_idc = = 1 ) [Ed. (JC):should_sps_cclm_colocated_chroma_flag also be signalled for 422 casesince it's used in the decoding process, to be confirmed]  sps_cclm_colocated_chroma_flag u(1)  sps_mts_enabled_flag u(1)  if(sps mts enabled flag ) {   sps_explicit_mts_intra_enabled_flag u(1)  sps_explicit_mts_inter_enabled_flag u(1)  }  sps_sbt_enabled_flag u(1) sps_affine_enabled_flag u(1)  if( sps_affine_enabled_flag ) {  sps_affine_type_flag u(1)   sps_affine_amvr_enabled_flag u(1)  sps_affine_prof_enabled_flag u(1)   if( sps_affine_prof_enabled_flag )   sps_prof_pic_present_flag u(1)  }  if( ChromaArrayType = = 3 ) {    

  u(1)    

  u(1)   

   sps_bcw_enabled_flag u(1)  sps_ibc_enabled_flag u(1) sps_ciip_enabled_flag u(1)  if( sps_mmvd_enabled_flag )  sps_fpel_mmvd_enabled_flag u(1)  sps_triangle_enabled_flag u(1) sps_lmcs_enabled_flag u(1)  spsfinst_enabled_flag u(1) sps_ladf_enabled_flag u(1)  if( sps_ladf_enabled_flag ) {  sps_num_ladf_intervals_minus2 u(2)  sps_ladf_lowest_interval_qp_offset se(v)   for( i = 0; i <sps_num_ladf_intervals_minus2 + 1; i++ ) {    sps_ladf_qp_offset[ i ]se(v)    sps_ladf_delta_threshold_minus1 [ i ] ue(v)   }  } sps_scaling_list_enabled_flag u(1) sps_loop_filter_across_virtual_boundaries_disabled_present_ u(1) flag if( sps_loop_filter_across_virtual_boundaries_disabled_present_ flag ){   sps_num_ver_virtual_boundaries u(2)   for( i = 0; i <sps_num_ver_virtual_boundaries; i++ )    sps_virtual_boundaries_pos_x[ i] u(13)   sps_num_hor_virtual_boundaries u(2)   for( i = 0; i <sps_num_hor_virtual_boundaries; i++ )    sps_virtual_boundaries_pos_y[ i] u(13)  }  if( sps_ptl_dpb_hrd_params_present_flag ) {  sps_general_hrd_params_present_flag u(1)   if(sps_general_hrd_params_present_flag ) {    general_hrd_parameters( )   if( sps_max_sub_layers_minus1 > 0 )    sps_sub_layer_cpb_params_present_flag u(1)    firstSubLayer =sps_sub_layer_cpb_params_present_flag ?    0 :     sps_max_sub_layers_minus1    ols_hrd_parameters( firstSubLayer,sps_max_sub_layers_ minus1 )   }  }  vui_parameters_present_flag u(1) if( vui_parameters_present_flag)   vui_parameters( ) sps_extension_flag u(1)  if( sps_extension_flag)   while(more_rbsp_data( ) )    sps_extension_data_flag u(1)  rbsp_trailing_bits() }

TABLE 6 Modification to picture parameter set RBSP syntax from VVC Draft7 De- scrip- tor pic_parameter_set_rbsp( ) {  pps_pic_parameter_set_idue(v)  pps_seq_parameter_set_id u(4)  pic_width_in_luma_samples ue(v) pic_height_in_luma_samples ue(v)  conformance_window_flag u(1)  if(conformance_window_flag ) {   conf_win_left_offset ue(v)  conf_win_right_offset ue(v)   conf_win_top_offset ue(v)  conf_win_bottom_offset ue(v)  }  scaling_window_flag u(1)  if(scaling_window_flag ) {   scaling_win_left_offset ue(v)  scaling_win_right_offset ue(v)   scaling_win_top_offset ue(v)  scaling_win_bottom_offset ue(v)  }  output_flag_present_flag u(1) mixed_nalu_types_in_pic_flag u(1) pps_subpic_id_signalling_present_flag u(1)  if(pps_subpics_id_signalling_present_flag ) {   pps_num_subpics_minus1ue(v)   pps_subpic_id_len_minus1 ue(v)   for( i = 0; i <=pps_num_subpic_minus1; i++ )    pps_subpic_id[ i ] u(v)  } no_pic_partition_flag u(1)  if( !no_pic_partition_flag ) {  pps_log2_ctu_size_minus5 u(2)   num_exp_tile_columns_minus1 ue(v)  num_exp_tile_rows_minus1 ue(v)   for( i = 0; i <=num_exp_tile_columns_minus1; i++ )    tile_column_width_minus1[ i ]ue(v)   for( i = 0; i <= num_exp_tile_rows_minus_1; i++ )   tile_row_height_minus1[ i ] ue(v)   rect_slice_flag u(1)   if(rect_slice_flag)    single_slice_per_subpic_flag u(1)   if(rect_slice_flag && !single_slice_per_subpic_flag ) {   num_slices_in_pic_minus1 ue(v)    tile_idx_delta_present_flag u(1)   for( i = 0; i < num_slices_in_pic_minus1; i++ ) {    slice_width_in_tiles_minus1[ i ] ue(v)    slice_height_in_tiles_minus1[ i ] ue(v)     if(slice_width_in_tiles_minus1[ i ] = = 0 &&      slice_height_in_tiles_minus1[ i ] = = 0 ) {    num_slices_in_tile_minus1[ i ] ue(v)     numSlicesInTileMinus1 =num_slices_in_tile_minus1[ i ]     for( j = 0; j <numSlicesInTileMinus1; j++ )      slice_height_in_ctu_minus1[ i ] ue(v)    }     if( tile_idx delta_present_flag && i < num_slices_in_pic_minus1 )      tile_idx_delta[ i ] se(v)    }   }  loop_filter_across_tiles_enabled_flag u(1)  loop_filter_across_slices_enabled_flag u(1)  } entropy_coding_sync_enabled_flag u(1)  if( !no_pic_partition_flag | |entropy_coding_sync_enabled_flag )   entry_point_offsets_present_flagu(1)  cabac_init_present_flag u(1)  for( i = 0; i < 2; i++ )  num_ref_idx_default_active_minus1[ i ] ue(v)  rpl1_idx_present_flagu(1)  init_qp_minus26 se(v)  if( sps_transform_skip_enabled_flag )  log2_transform_skip_max_size_minus2 ue(v)  cu_qp_delta_enabled_flagu(1)   

  u(1)  if( pps_chroma_present_flag ) {    

  se(v)    

  se(v)    

  u(1)    

  u(1)    

  u(1)   

   if( pps_joint_cbc_qp_offset_present_flag )  pps_joint_cbcr_qp_offset_value se(v)  if(pps_cu_chroma_qp_offset_list_enabled_flag ) {  chroma_qp_offset_list_len_minus1 ue(v)   for( i = 0; i <=chroma_qp_offset_list_len_minus1; i++ ) {    cb_qp_offset_list[ i ]se(v)    cr_qp_offset_list[ i ] se(v)    if(pps_joint_cbcr_qp_offset_present_flag )     joint_cbcr_qp_offset_list[ i] se(v)   }  }  pps_weighted_pred_flag u(1)  pps_weighted_bipred_flagu(1)  deblocking_filter_control_present_flag u(1)  if(deblocking_filter_control_present_flag ) {  deblocking_filter_override_enabled_flag u(1)  pps_deblocking_filter_disabled_flag u(1)   if(!pps_deblocking_filter_disabled_flag ) {    pps_beta_offset_div2 se(v)   pps_tc_offset_div2 se(v)   }  } constant_slice_header_params_enabled_flag u(1)  if(constant_slice_header_params_enabled_flag ) {  pps_dep_quant_enabled_idc u(2)   for( i = 0; i < 2; i++ )   pps_ref_pic_list_sps_idc[ i ] u(2)   pps_mvd_l1_zero_idc u(2)  pps_collocated_from_l0_idc u(2)  pps_six_minus_max_num_merge_cand_plus1 ue(v)  pps_max_num_merge_cand_minus_max_num_triangle_ ue(v) cand_plus1  } picture_header_extension_present_flag u(1) slice_header_extension_present_flag u(1)  pps_extension_flag u(1)  if(pps_extension_flag )   while( more_rbsp_data( ) )   pps_extension_data_flag u(1)  rbsp_trailing_bits( ) }

TABLE 7 Modification to adaptation parameter set syntax from VVC Draft 7Descriptor adaptation_parameter_set_rbsp( ) { adaptation_parameter_set_id u(5)  aps_params_type u(3)   

  u(1)  if( aps_params_type = = ALF_APS )   alf_data( )  else if(aps_params_type = = LMCS_APS )   lmcs_data( )  else if( aps_params_type= = SCALING_APS )    scaling_list_data( )  aps_extension_flag u(1)  if(aps_extension_flag)   while( more_rbsp_data( ) )   aps_extension_data_flag u(1)  rbsp_trailing_bits( ) }

TABLE 8 Modification to adaptive loop filter data syntax from VVC Draft7 Descriptor alf_data( ) {  alf_luma_filter_signal_flag u(1)  if(aps_chroma_present_flag )    

  u(1)  if( alf_luma_filter_signal_flag ) {   alf_luma_clip_flag u(1)  alf_luma_num_filters_signalled_minus1 ue(v)   if(alf_luma_num_filters_signalled_minus1 > 0 ) {    for( filtIdx = 0;filtIdx < NumAlfFilters; filtIdx++ )     alf_luma_coeff_delta_idx[filtIdx ] u(v)   }   for( sfIdx = 0; sfIdx <=alf_luma_num_filters_signalled_minus1; sfIdx++ ) {    for( j = 0; j <12; j++) {     alf_luma_coeff_abs[ sfIdx ][ j ] uek(v)     if(alf_luma_coeff_abs[ sfIdx ][ j ] )      alf_luma_coeff_sign[ sfIdx ][ j] u(1)    }   }   if( alf_luma_clip_flag) {    for( sfIdx = 0; sfIdx <=alf_luma_num_filters_signalled_minus1; sfIdx++ ) {    for( j = 0; j <12; j++)     alf_luma_clip_idx[ sfIdx ][ j ] u(2)    }   }  }  if(alf_chroma_filter_signal_flag) {   alf_chroma_num_alt_filters_minus1ue(v)    for( altIdx = 0; altIdx <= alf_chroma_num_alt_filters_minus1;altIdx++ )  {    alf_chroma_chp_flag[ altIdx ] u(1)    for( j = 0; j <6; j++ ) {     alf_chroma_coeff_abs[ altIdx ][ j ] uek(v)     if(alf_chroma coeff_abs[ altIdx ][ j ] > 0 )      alf_chroma_coeff_sign[altIdx ][ j ] u(1)    }    if( alf_chroma clip flag[ altIdx ] ) {    for( j = 0; j < 6; j++)      alf_chroma_clip_idx[ altIdx ][ j ] u(2)   }   }  } }

pps_chroma_present_flag may specify whether chroma component is present.When pps_chroma_present_flag equal to 1, chroma related syntax may bepresent in PPS. pps_chroma_present_flag equal to 0 may specify thatchroma component does not present. It may be a requirement of bitstreamconformance that pps_chroma_present_flag equal to 0 when ChromaArrayTypeis equal to 0.

pps_cb_qp_offset and pps_cr_qp_offset may specify the offsets to theluma quantization parameter Qp′_(Y) used for deriving Qp′_(Cb) andQp′_(Cr), respectively. The values of pps_cb_qp_offset andpps_cr_qp_offset may be in the range of −12 to +12, inclusive. WhenChromaArrayType is equal to 0, pps_cb_qp_offset and pps_cr_qp_offset maybe not used in the decoding process and decoders may ignore their value.

pps_joint_cbcr_qp_offset_present_flag equal to 1 may specify thatpps_joint_cbcr_qp_offset_value and joint_cbcr_qp_offset_list[i] arepresent in the PPS RBSP syntax structure.pps_joint_cbcr_qp_offset_present_flag equal to 0 may specify thatpps_joint_cbcr_qp_offset_value and joint_cbcr_qp_offset_list[i] are notpresent in the PPS RBSP syntax structure. Whenpps_joint_cbcr_qp_offset_present_flag is not present, it may be inferredto be be equal to 0.

pps_slice_chroma_qp_offsets_present_flag equal to 1 may indicate thatthe slice_cb_qp_offset and slice_cr_qp_offset syntax elements arepresent in the associated slice headers.pps_slice_chroma_qp_offsets_present_flag equal to 0 may indicate thatthese syntax elements are not present in the associated slice headers.When pps_slice_chroma_qp_offsets_present_flag is not present, it may beinferred to be equal to 0.

pps_cu_chroma_qp_offset_list_enabled_flag equal to 1 may specify thatthe pic_cu_chroma_qp_offset_subdiv_intra_slice andpic_cu_chroma_qp_offset_subdiv_inter_slice syntax elements are presentin PHs referring to the PPS and that cu_chroma_qp_offset_flag may bepresent in the transform unit syntax and the palette coding syntax.pps_cu_chroma_qp_offset_list_enabled_flag equal to 0 may specify thatthe pic_cu_chroma_qp_offset_subdiv_intra_slice andpic_cu_chroma_qp_offset_subdiv_inter_slice syntax elements are notpresent in picture headers referring to the PPS and that thecu_chroma_qp_offset_flag is not present in the transform unit syntax andthe palette coding syntax. Whenpps_cu_chroma_qp_offset_list_enabled_flag is not present, it may beinferred to be equal to 0.

aps_chroma_present_flag specifies whether chroma component is present.When aps_chroma_present_flag equal to 1, chroma related syntax may bepresent in APS. aps_chroma_present_flag equal to 0 may specify thatchroma related syntaxes are not present. It may be a requirement ofbitstream conformance that pps_chroma_present_flag equal to 0 whenChromaArrayType equal to 0.

alf_chroma_filter_signal_flag equal to 1 may specify that a chromafilter is signaled. alf_chroma_filter_signal_flag equal to 0 may specifythat a chroma filter is not signaled. When alf_chroma_filter_signal_flagis not present, it may be inferred to be equal to 0.

When ChromaArrayType is 0, a video component may be encoded as if it ismonochrome or 4:4:4 with separately coded colour planes.

In FIG. 5A, chroma QP related syntax parsing may be disabled whenpps_chroma_present_flag is 0 to avoid unnecessary decoding process. Thesyntax such as pps_cb_qp_offset, pps_cr_qp_offset,pps_joint_cbcr_qp_offset_present_flag,pps_slice_chroma_qp_offsets_present_flag,pps_cu_chroma_qp_offset_list_enabled_flag may be inferred to 0, and thusnot applied in QP derivation process in decoder side.

In FIG. 5B, chroma ALF filter as a chroma filter may be disabled whenaps_chroma_present_flag is 0 to avoid unnecessary decoding process.Therefore, the syntax alf_chroma_filter_signal_flag are inferred to 0.

In FIG. 5C, VVC Draft 7 has several coding tools only applied to whenchroma format is 4:4:4 without separate colour plane such as BDPCM forchroma, PLT and ACT. The syntax related to these tools should not beparsed when chroma format is 4:4:4 with separate colour plane whichmeans there chroma component present as luma component. Therefore,parsing of these syntax should be performed only when ChromaArrayTypeequals to 3 to avoid unnecessary decoding process.

In detail, FIGS. 5A-5C are flowcharts of example processes 500A, 500B,and 500C for decoding an encoded video bitstream, according toembodiments. In embodiments, any of processes 500A, 500B, and 500C, orany portions of processes 500A, 500B, and 500C, may be combined in anycombination or permutation and in any order as desired. In someimplementations, one or more process blocks of FIGS. 5A-5C may beperformed by decoder 210. In some implementations, one or more processblocks of FIGS. 5A-5C may be performed by another device or a group ofdevices separate from or including decoder 210, such as encoder 203.

As shown in FIG. 5A, process 500A may include obtaining an encoded videobitstream including a coded video sequence (block 511).

As further shown in FIG. 5A, process 500A may include determiningwhether pps_chroma_present_flag is equal to 1 (block 512).

As further shown in FIG. 5A, if pps_chroma_present_flag is not equal to1 (NO at block 512), process 500A may proceed to block 513. However, ifpps_chroma_present_flag is equal to 1 (YES at block 512), process 500Amay proceed to block 515.

As further shown in FIG. 5A, process 500A may include inferring a valueof chroma QP related syntax to be equal to 0 without parsing the chromaQP related syntax (block 513), and then decoding the video sequencewithout applying the chroma QP related syntax (block 514).

As further shown in FIG. 5A, process 500A may include parsing a value ofthe chroma QP related syntax (block 515).

As further shown in FIG. 5A, process 500A may include determiningwhether a value of the chroma QP related syntax is equal to 0 (block516).

As further shown in FIG. 5A, if the value of the chroma QP relatedsyntax is determined to be equal to 0 (YES at block 516), process 500Amay proceed to block 514. However, if the value of the chroma QP relatedsyntax is determined not to be equal to 0 (NO at block 516), process500A may proceed to block 517, in which the chroma QP related syntax isapplied while decoding the video sequence.

As shown in FIG. 5B, process 500B may include obtaining an encoded videobitstream including a coded video sequence (block 521).

As further shown in FIG. 5B, process 500B may include determiningwhether aps_chroma_present_flag is equal to 1 (block 522).

As further shown in FIG. 5B, if aps_chroma_present_flag is not equal to1 (NO at block 522), process 500B may proceed to block 523. However, ifaps_chroma_present_flag is equal to 1 (YES at block 522), process 500Bmay proceed to block 525.

As further shown in FIG. 5B, process 500B may include inferring a valueof alf_chroma_filter_signal_flag to be equal to 0 without parsingalf_chroma_filter_signal_flag (block 523), and then decoding the videosequence without applying the ALF chroma filter (block 524).

As further shown in FIG. 5B, process 500B may include parsing a value ofalf_chroma_filter_signal_flag (block 525).

As further shown in FIG. 5B, process 500B may include determiningwhether a value of the alf_chroma_filter_signal_flag is equal to 1(block 526).

As further shown in FIG. 5B, if the value of the chroma QP relatedsyntax is determined not to be equal to 1 (NO at block 526), process500B may proceed to block 524. However, if the value of thealf_chroma_filter_signal_flag is determined to be equal to 1 (YES atblock 526), process 500B may proceed to block 527, in which the ALFchroma filter is applied while decoding the video sequence.

As shown in FIG. 5C, process 500C may include obtaining an encoded videobitstream including a coded video sequence (block 531).

As further shown in FIG. 5C, process 500C may include determiningwhether chromaArrayType is equal to 3 (block 532).

As further shown in FIG. 5C, if chromaArrayType is not equal to 3 (NO atblock 532), process 500C may proceed to block 533. However, ifchromaArrayType is equal to 3 (YES at block 532), process 500C mayproceed to block 535.

As further shown in FIG. 5C, process 500C may include inferring a valueof syntax related to chroma format of 4:4:4 without separate color planeto be equal to 0 without parsing the syntax related to chroma format of4:4:4 without separate color plane (block 533), and then decoding thevideo sequence without applying a coding tool related to chroma formatof 4:4:4 without separate color plane (block 534).

As further shown in FIG. 5C, process 500C may include parsing a value ofthe syntax related to chroma format of 4:4:4 without separate colorplane (block 535).

As further shown in FIG. 5C, process 500C may include determiningwhether a value of the syntax related to chroma format of 4:4:4 withoutseparate color plane is equal to 1 (block 536).

As further shown in FIG. 5C, if the value of the syntax related tochroma format of 4:4:4 without separate color plane is determined not tobe equal to 1 (NO at block 536), process 500C may proceed to block 534.However, if the value of the syntax related to chroma format of 4:4:4without separate color plane is determined to be equal to 1 (YES atblock 536), process 500C may proceed to block 537, in which the toolrelated to chroma format of 4:4:4 without separate color plane isapplied while decoding the video sequence.

FIG. 6 is a flowchart of an example process 600 for decoding an encodedvideo bitstream, according to embodiments. In embodiments, any portionof process 600 may be combined or arranged in any combination orpermutation and in any order as desired. In some implementations, one ormore process blocks of FIG. 6 may be performed by decoder 210. In someimplementations, one or more process blocks of FIG. 6 may be performedby another device or a group of devices separate from or includingdecoder 210, such as encoder 203.

As shown in FIG. 6 , process 600 may include obtaining an encoded videobitstream (block 601).

As further shown in FIG. 6 , process 600 may include determining whethera chroma array type of a video sequence included in the encoded videobitstream is a first chroma array type indicating that the videosequence includes multiple color planes and that the multiple colorplanes are jointly encoded (block 602).

As further shown in FIG. 6 , if the chroma array type is not the firstchroma array type (NO at block 602), process 600 may proceed to block603. However, if the chroma array type is the first chroma array type(YES at block 602), process 600 may proceed to block 605.

As further shown in FIG. 6 , process 600 may include inferring a valueof at least one syntax element to be 0 without parsing the at least onesyntax element from the encoded video bitstream (block 603), and thendecoding the video sequence without applying at least one toolcorresponding to the at least one syntax element (block 604).

As further shown in FIG. 6 , process 600 may include parsing the atleast one syntax element (block 605).

As further shown in FIG. 6 , process 600 may include determining whethera value of the at least one syntax element is equal to 0 (block 602).

As further shown in FIG. 6 , if the value of the at least one syntaxelement is determined to be equal to 0 (YES at block 606), process 600may proceed to block 604. However, if the value of the at least onesyntax element is determined not to be equal to 0 (NO at block 606),process 600 may proceed to block 607, in which the video sequence isdecoded using a tool based on the value of the at least one syntaxelement.

In embodiments, the chroma array type may be determined based on a firstflag indicating whether the video sequence includes the multiple colorplanes, and a first syntax element indicating a chroma format of thevideo sequence.

In embodiments, the at least one tool may include at least one fromamong block-based delta pulse code modulation, palette mode coding, andadaptive color transform.

In embodiments, based on the chroma array type being a second chromaarray type indicating that the video sequence does not include themultiple color planes, or that the multiple color planes are separatelyencoded, a value of a second flag signaled in a picture parameter set(PPS) may be set equal to 0.

In embodiments, the at least one syntax element may be signaled in thePPS, and the at least one tool may correspond to a chroma quantizationparameter of the video sequence.

In embodiments, based on the chroma array type being a second chromaarray type indicating that the video sequence does not include themultiple color planes, or that the multiple color planes are separatelyencoded, a value of a third flag signaled in an adaptation parameter set(APS) may be set equal to zero.

In embodiments, the at least one syntax element may be signaled in theAPS, and the at least one tool may correspond to an adaptive loopfilter.

Although FIGS. 5A-5C and 6 show example blocks of processes 500A, 500B,500C, and 600, in some implementations, processes 500A, 500B, 500C, and600 may include additional blocks, fewer blocks, different blocks, ordifferently arranged blocks than those depicted in FIGS. 5A-5C and 6.Additionally, or alternatively, two or more of the blocks of processes500A, 500B, 500C, and 600 may be performed in parallel.

Further, the proposed methods may be implemented by processing circuitry(e.g., one or more processors or one or more integrated circuits). Inone example, the one or more processors execute a program that is storedin a non-transitory computer-readable medium to perform one or more ofthe proposed methods.

The techniques described above, can be implemented as computer softwareusing computer-readable instructions and physically stored in one ormore computer-readable media. For example, FIG. 7 shows a computersystem 700 suitable for implementing certain embodiments of thedisclosed subject matter.

The computer software can be coded using any suitable machine code orcomputer language, that may be subject to assembly, compilation,linking, or like mechanisms to create code comprising instructions thatcan be executed directly, or through interpretation, micro-codeexecution, and the like, by computer central processing units (CPUs),Graphics Processing Units (GPUs), and the like.

The instructions can be executed on various types of computers orcomponents thereof, including, for example, personal computers, tabletcomputers, servers, smartphones, gaming devices, internet of thingsdevices, and the like.

The components shown in FIG. 7 for computer system 700 are exemplary innature and are not intended to suggest any limitation as to the scope ofuse or functionality of the computer software implementing embodimentsof the present disclosure. Neither should the configuration ofcomponents be interpreted as having any dependency or requirementrelating to any one or combination of components illustrated in theexemplary embodiment of a computer system 700.

Computer system 700 may include certain human interface input devices.Such a human interface input device may be responsive to input by one ormore human users through, for example, tactile input (such as:keystrokes, swipes, data glove movements), audio input (such as: voice,clapping), visual input (such as: gestures), olfactory input (notdepicted). The human interface devices can also be used to capturecertain media not necessarily directly related to conscious input by ahuman, such as audio (such as: speech, music, ambient sound), images(such as: scanned images, photographic images obtain from a still imagecamera), video (such as two-dimensional video, three-dimensional videoincluding stereoscopic video).

Input human interface devices may include one or more of (only one ofeach depicted): keyboard 701, mouse 702, trackpad 703, touch screen 710and associated graphics adapter 750, data-glove 1204, joystick 705,microphone 706, scanner 707, camera 708.

Computer system 700 may also include certain human interface outputdevices. Such human interface output devices may be stimulating thesenses of one or more human users through, for example, tactile output,sound, light, and smell/taste. Such human interface output devices mayinclude tactile output devices (for example tactile feedback by thetouch-screen 710, data-glove 1204, or joystick 705, but there can alsobe tactile feedback devices that do not serve as input devices), audiooutput devices (such as: speakers 709, headphones (not depicted)),visual output devices (such as screens 710 to include cathode ray tube(CRT) screens, liquid-crystal display (LCD) screens, plasma screens,organic light-emitting diode (OLED) screens, each with or withouttouch-screen input capability, each with or without tactile feedbackcapability—some of which may be capable to output two dimensional visualoutput or more than three dimensional output through means such asstereographic output; virtual-reality glasses (not depicted),holographic displays and smoke tanks (not depicted)), and printers (notdepicted).

Computer system 700 can also include human accessible storage devicesand their associated media such as optical media including CD/DVD ROM/RW720 with CD/DVD or the like media 721, thumb-drive 722, removable harddrive or solid state drive 723, legacy magnetic media such as tape andfloppy disc (not depicted), specialized ROM/ASIC/PLD based devices suchas security dongles (not depicted), and the like.

Those skilled in the art should also understand that term “computerreadable media” as used in connection with the presently disclosedsubject matter does not encompass transmission media, carrier waves, orother transitory signals.

Computer system 700 can also include interface(s) to one or morecommunication networks (955). Networks can for example be wireless,wireline, optical. Networks can further be local, wide-area,metropolitan, vehicular and industrial, real-time, delay-tolerant, andso on. Examples of networks include local area networks such asEthernet, wireless LANs, cellular networks to include global systems formobile communications (GSM), third generation (3G), fourth generation(4G), fifth generation (5G), Long-Term Evolution (LTE), and the like, TVwireline or wireless wide area digital networks to include cable TV,satellite TV, and terrestrial broadcast TV, vehicular and industrial toinclude CANBus, and so forth. Certain networks commonly require externalnetwork interface adapters (954) that attached to certain generalpurpose data ports or peripheral buses (949) (such as, for exampleuniversal serial bus (USB) ports of the computer system 700; others arecommonly integrated into the core of the computer system 700 byattachment to a system bus as described below (for example Ethernetinterface into a PC computer system or cellular network interface into asmartphone computer system). As an example, network 755 may be connectedto peripheral bus 749 using network interface 754. Using any of thesenetworks, computer system 700 can communicate with other entities. Suchcommunication can be uni-directional, receive only (for example,broadcast TV), uni-directional send-only (for example CANbus to certainCANbus devices), or bi-directional, for example to other computersystems using local or wide area digital networks. Certain protocols andprotocol stacks can be used on each of those networks and networkinterfaces (954) as described above.

Aforementioned human interface devices, human-accessible storagedevices, and network interfaces can be attached to a core 740 of thecomputer system 700.

The core 740 can include one or more Central Processing Units (CPU) 741,Graphics Processing Units (GPU) 742, specialized programmable processingunits in the form of Field Programmable Gate Areas (FPGA) 743, hardwareaccelerators 744 for certain tasks, and so forth. These devices, alongwith Read-only memory (ROM) 745, Random-access memory (RAM) 746,internal mass storage such as internal non-user accessible hard drives,solid-state drives (SSDs), and the like 747, may be connected through asystem bus 748. In some computer systems, the system bus 748 can beaccessible in the form of one or more physical plugs to enableextensions by additional CPUs, GPU, and the like. The peripheral devicescan be attached either directly to the core's system bus 748, or througha peripheral bus 749. Architectures for a peripheral bus includeperipheral component interconnect (PCI), USB, and the like.

CPUs 741, GPUs 742, FPGAs 743, and accelerators 744 can execute certaininstructions that, in combination, can make up the aforementionedcomputer code. That computer code can be stored in ROM 745 or RAM 746.Transitional data can be also be stored in RAM 746, whereas permanentdata can be stored for example, in the internal mass storage 747. Faststorage and retrieve to any of the memory devices can be enabled throughthe use of cache memory, that can be closely associated with one or moreCPU 741, GPU 742, mass storage 747, ROM 745, RAM 746, and the like.

The computer readable media can have computer code thereon forperforming various computer-implemented operations. The media andcomputer code can be those specially designed and constructed for thepurposes of the present disclosure, or they can be of the kind wellknown and available to those having skill in the computer software arts.

As an example and not by way of limitation, the computer system havingarchitecture 700, and specifically the core 740 can providefunctionality as a result of processor(s) (including CPUs, GPUs, FPGA,accelerators, and the like) executing software embodied in one or moretangible, computer-readable media. Such computer-readable media can bemedia associated with user-accessible mass storage as introduced above,as well as certain storage of the core 740 that are of non-transitorynature, such as core-internal mass storage 747 or ROM 745. The softwareimplementing various embodiments of the present disclosure can be storedin such devices and executed by core 740. A computer-readable medium caninclude one or more memory devices or chips, according to particularneeds. The software can cause the core 740 and specifically theprocessors therein (including CPU, GPU, FPGA, and the like) to executeparticular processes or particular parts of particular processesdescribed herein, including defining data structures stored in RAM 746and modifying such data structures according to the processes defined bythe software. In addition or as an alternative, the computer system canprovide functionality as a result of logic hardwired or otherwiseembodied in a circuit (for example: accelerator 744), which can operatein place of or together with software to execute particular processes orparticular parts of particular processes described herein. Reference tosoftware can encompass logic, and vice versa, where appropriate.Reference to a computer-readable media can encompass a circuit (such asan integrated circuit (IC)) storing software for execution, a circuitembodying logic for execution, or both, where appropriate. The presentdisclosure encompasses any suitable combination of hardware andsoftware.

While this disclosure has described several exemplary embodiments, thereare alterations, permutations, and various substitute equivalents, whichfall within the scope of the disclosure. It will thus be appreciatedthat those skilled in the art will be able to devise numerous systemsand methods which, although not explicitly shown or described herein,embody the principles of the disclosure and are thus within the spiritand scope thereof.

Acronyms:

HEVC: High Efficiency Video Coding

VVC: Versatile Video Coding

JVET: Joint Video Exploration Team

CU: Coding Unit

VTM: Versatile Video Coding Test Model

SPS: sequence parameter set

BDPCM: Block-based Delta Pulse Code Modulation

ACT: Adaptive Color Transform

4:4:4: video with chroma format equal to 4:4:4

ALF: adaptive loop filter

QP: quantization parameter

PLT: palette mode coding

What is claimed is:
 1. A method of generating an encoded videobitstream, the method being performed by at least one processor andcomprising: obtaining video data; determining whether a chroma arraytype of a video sequence included in the video data is a first chromaarray type indicating that the video sequence includes multiple colorplanes and that the multiple color planes are jointly encoded; setting afirst flag indicating whether the video sequence includes the multiplecolor planes, and a first syntax element indicating a chroma format ofthe video sequence; and generating the encoded video bitstream based onthe video sequence, the first flag, and the first syntax element,wherein based on determining that the chroma array type is not the firstchroma array type, the video sequence is encoded without applying atleast one tool corresponding to at least one syntax element, and thefirst flag and the first syntax element indicate to a decoder to set avalue of the at least one syntax element to zero without parsing the atleast one syntax element from the encoded video bitstream.
 2. The methodof claim 1, wherein based on determining that the chroma array type isthe first chroma array type, the video sequence is encoded by applyingthe at least one tool corresponding to the at least one syntax element,and the first flag and the first syntax element are set to indicate tothe decoder to parse the at least one syntax element from the encodedvideo bitstream.
 3. The method of claim 1, wherein the at least one toolcomprises at least one from among block-based delta pulse codemodulation, palette mode coding, and adaptive color transform.
 4. Themethod of claim 1, further comprising: based on the chroma array typebeing a second chroma array type indicating that the video sequence doesnot include the multiple color planes, or that the multiple color planesare separately encoded, setting a value of a second flag signaled in apicture parameter set (PPS) equal to zero.
 5. The method of claim 4,wherein the at least one syntax element is signaled in the PPS, andwherein the at least one tool corresponds to a chroma quantizationparameter of the video sequence.
 6. The method of claim 1, furthercomprising: based on the chroma array type being a second chroma arraytype indicating that the video sequence does not include the multiplecolor planes, or that the multiple color planes are separately encoded,setting a value of a third flag signaled in an adaptation parameter set(APS) equal to zero.
 7. The method of claim 6, wherein the at least onesyntax element is signaled in the APS, and wherein the at least one toolcorresponds to an adaptive loop filter.
 8. A device for generating anencoded video bitstream, the device comprising: at least one memoryconfigured to store program code; and at least one processor configuredto read the program code and operate as instructed by the program code,the program code including: obtaining code configured to cause the atleast one processor to obtain video data; determining code configured tocause the at least one processor to determine whether a chroma arraytype of a video sequence included in the video data is a first chromaarray type indicating that the video sequence includes multiple colorplanes and that the multiple color planes are jointly encoded; firstsetting code configured to cause the at least one processor to set afirst flag indicating whether the video sequence includes the multiplecolor planes, and a first syntax element indicating a chroma format ofthe video sequence; and generating code configured to cause the at leastone processor to generate the encoded video bitstream based on the videosequence, the first flag, and the first syntax element, wherein based ondetermining that the chroma array type is not the first chroma arraytype, the video sequence is encoded without applying at least one toolcorresponding to at least one syntax element, and the first flag and thefirst syntax element indicate to a decoder to set a value of the atleast one syntax element to zero without parsing the at least one syntaxelement from the encoded video bitstream.
 9. The device of claim 8,wherein based on the video sequence is encoded by applying the at leastone tool corresponding to the at least one syntax element, and the firstflag and the first syntax element are set to indicate to the decoder toparse the at least one syntax element from the encoded video bitstream.10. The device of claim 8, wherein the at least one tool comprises atleast one from among block-based delta pulse code modulation, palettemode coding, and adaptive color transform.
 11. The device of claim 8,further comprising: second setting code configured to cause the at leastone processor to, based on the chroma array type being a second chromaarray type indicating that the video sequence does not include themultiple color planes, or that the multiple color planes are separatelyencoded, set a value of a second flag signaled in a picture parameterset (PPS) equal to zero.
 12. The device of claim 11, wherein the atleast one syntax element is signaled in the PPS, and wherein the atleast one tool corresponds to a chroma quantization parameter of thevideo sequence.
 13. The device of claim 8, further comprising: thirdsetting code configured to cause the at least one processor to, based onthe chroma array type being a second chroma array type indicating thatthe video sequence does not include the multiple color planes, or thatthe multiple color planes are separately encoded, set a value of a thirdflag signaled in an adaptation parameter set (APS) equal to zero. 14.The device of claim 13, wherein the at least one syntax element issignaled in the APS, and wherein the at least one tool corresponds to anadaptive loop filter.
 15. A non-transitory computer-readable mediumstoring instructions, the instructions comprising: one or moreinstructions that, when executed by one or more processors of a devicefor generating an encoded video bitstream, cause the one or moreprocessors to: obtain video data; determine whether a chroma array typeof a video sequence included in the video data is a first chroma arraytype indicating that the video sequence includes multiple color planesand that the multiple color planes are jointly encoded; set a first flagindicating whether the video sequence includes the multiple colorplanes, and a first syntax element indicating a chroma format of thevideo sequence; and generate the encoded video bitstream based on thevideo sequence, the first flag, and the first syntax element, whereinbased on determining that the chroma array type is not the first chromaarray type, the video sequence is encoded without applying at least onetool corresponding to at least one syntax element, and the first flagand the first syntax element indicate to a decoder to set a value of theat least one syntax element to zero without parsing the at least onesyntax element from the encoded video bitstream.
 16. The non-transitorycomputer-readable medium of claim 15, wherein based on determining thatthe chroma array type is the first chroma array type, the video sequenceis encoded by applying the at least one tool corresponding to the atleast one syntax element, and the first flag and the first syntaxelement are set to indicate to the decoder to parse the at least onesyntax element from the encoded video bitstream.
 17. The non-transitorycomputer-readable medium of claim 15, wherein based on determining thatthe chroma array type is the first chroma array type, the video sequenceis encoded by applying the at least one tool corresponding to the atleast one syntax element, and the first flag and the first syntaxelement are set to indicate to the decoder to parse the at least onesyntax element from the encoded video bitstream.
 18. The non-transitorycomputer-readable medium of claim 15, wherein the at least one toolcomprises at least one from among block-based delta pulse codemodulation, palette mode coding, and adaptive color transform.
 19. Thenon-transitory computer-readable medium of claim 15, wherein theinstructions are further configured to cause the one or more processorsto: based on the chroma array type being a second chroma array typeindicating that the video sequence does not include the multiple colorplanes, or that the multiple color planes are separately encoded, set avalue of a second flag signaled in a picture parameter set (PPS) equalto zero.
 20. The non-transitory computer-readable medium of claim 15,wherein the instructions are further configured to cause the one or moreprocessors to: based on the chroma array type being a second chromaarray type indicating that the video sequence does not include themultiple color planes, or that the multiple color planes are separatelyencoded, set a value of a third flag signaled in an adaptation parameterset (APS) equal to zero.